Recently, color prints and complicated prints have been increasingly desired in the field of photomechanical process. Accordingly, demand for improvement of quality and stability of silver halide photosensitive materials used for printing (hereinafter referred to as "printing photosensitive material") which are intermediate media in printing increases steadily. Hitherto, general printing photosensitive materials have been imparted with so-called lith developability for obtaining prints of high quality. However, in the lith development, it is mechanically impossible to allow the developer to contain a sulfite ion at a high concentration as a preservative and it is well known for one skilled in the art that the developer is considerably low in stability. Some proposals have been made on the techniques to solve the instability of lith development and to obtain images having a contrast as high as that obtained by lith development. These are disclosed in patent publications. For example, use of hydrazine compounds to obtain high-contrast images is disclosed in Japanese Patent Kokai Nos. 53-16623, 53-20921, 53-20922, 53-49429, 53-66732, 55-90940, 56-67843, 57-99635, 62-73256, 62-275247, 62-178246, 62-180361, 63-121838, 63-223744, 63-234244, 63-253357, 64-90439, 1-105943, 2-25843, 2-120736, 2-37, 2-8834, 3-184039 and 4-51143. It is necessary for obtaining high-contrast images that the developers containing the hydrazine compounds have a relatively high pH value. The developers having a high pH value suffer from the problems that they absorb carbon dioxide in the air to cause decrease of pH and are not necessarily sufficient in stability against air oxidation to result in reduction of service life.
For forming high-contrast images with developers of lower pH value to solve these problems, attempts have been made to render more active the hydrazine derivatives used, as disclosed in Japanese Patent Kokai Nos. 60-179734 and 62-948 and U.S. Pat. Nos. 4,385,108, 4,269,929, 4,988,604, 4,994,365 and 5,104,769. However, there is a limit in increasing the contrast of images using developers of low pH only by improving the hydrazine derivatives. Therefore, contrast promoters have been developed. It is known to add secondary or tertiary amino compounds to developers as described in Japanese Patent Kokai Nos. 56-106244, 60-218642 and 61-267759 and to also add the amino compounds to photosensitive materials as disclosed in Japanese Patent Kokai Nos. 60-140340, 62-222241 and 63-124045 and U.S. Pat. No. 4,975,354. However, these methods still have the problems that no satisfactorily high contrast can be obtained, the compounds must be used in a large amount and photographic performances change greatly when compositions of the developers change after running or owing to air oxidation. Under the circumstances, more effective promoters have been desired.